Preforms for blow-molded plastic bottles (such as used for soft drinks and water) are sometimes stored in containers before they are turned into bottles. It is useful for inventory control purposes to know the number of preforms in a container. As preform molds may have many cavities, and a cycle time of only about five to ten seconds, it is difficult to transport preforms away from the mold, count them, and move them into a container, particularly since they are still warm and susceptible to nicks and scratches, particularly in the threaded are of the neck, which can implicate the ability of the bottle to be properly sealed.